This application claims priority to Korean Application No. 99-18490 filed May 21, 1999, incorporated by reference herein.
1. Field of the Invention
The present invention relates to streaming of MPEG-1 data through a network. Particularly, it relates to an apparatus and method for streaming MPEG-1 data in which, when the MPEG-1 data is transmitted on the network, the MPEG-1 data is converted into intermediate data, a server transfers the intermediate data in the form of packet with synchronizing video intermediate data and audio intermediate data with each other, thereby allowing a client to be able to receive and process the intermediate data through a simple conversion.
2. Discussion of Related Art
In streaming of MPEG-1 data (video data and audio data) through a network, in general, a transmitting side transmits the MPEG-1 data in the form of packet using corresponding protocol with regard to a limited data streaming rate and amount of streaming data of the network. A receiving side includes an additional apparatus for receiving the MPEG-1 data in the form of packet and an apparatus for decompressing the compressed MPEG-1 data to receive and process the MPEG-1 data transmitted.
That is, a system for streaming the MPEG-1 data through the network consists of the server and client. The server stores a large amount of MPEG-1 data at a data storage thereof and, when the client requests specific data, extracts the corresponding MPEG-1 data to transfer it to the client. Accordingly, the client needs an additional decoding apparatus for decoding the MPEG-1 data to process it. This complicates the configuration of the client computer. Further, the client should synchronize the video data and audio data with each other, brining about complexity due to the synchronization. Moreover, the client side requires a high-speed central processing unit to decode the MPEG-1 data, resulting in difficulty in realization of its hardware and increase in product cost.
Accordingly, the present invention is directed to an apparatus and method for streaming MPEG-1 data that substantially obviates one or more of the problems due to limitations and disadvantages of the related art.
An object of the present invention is to provide an apparatus and method for streaming MPEG-1 data in which, when the MPEG-1 data is transmitted through a network, the MPEG-1 data are converted into intermediate data, a server transfers the intermediate data in the form of packet with synchronizing video intermediate data and audio intermediate data with each other, thereby allowing a client to be able to receive and process the intermediate data through a simple conversion.
In order to achieve the above object of the present invention, the server transmits intermediate data (YUV, PCM) to the network in view of synchronization of video data and audio data so that the synchronization between the video (YUV) data and audio (PCM) data is achieved at the client side only by sequentially processing the intermediate data entering the network.
Further, the server uses a PTS (Present Time Stamp) placed at a system stream part of the MPEG-1 file for the synchronization of the video data and audio data. Specifically, the video data and audio data are compressed into a video stream and audio stream, respectively, in MPEG-1 and synchronized according to the PTS of the system stream. Accordingly, the server uses this PTS to synchronize YUV (Y indicates luminance signal and U and V indicate color difference signals) and PCM (pulse coded modulation data corresponding to a voice signal), respectively outputted from a video decoder and audio decoder, with each other, and transmits them to the network.
Additional features and advantages of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.